"There were several notes and letters from Russia's foreign and defence ministries noting that the planned drills were violating Russia's sovereignty and international law. The readiness to respond to our exercises was also spoken about," she told the news agency.

She also confirmed that those documents actually contained Russia's threats of using force against Ukraine.

Ukraine's foreign ministry has already prepared a diplomatic note for Russia to be sent off in the next few hours, the official claimed.

Our position is that the sovereign territory of Ukraine and all missile firing exercises are held in total accordance with Ukrainian and international law. In particular, they are being held in accordance with the Articles 1 and 2 fo the 1944 Chicago convention on the international civil aviation, within Ukraine's sovereign terrestrial and maritime territory and its airspace.